<?php
// +----------------------------------------------------------------------
// | ThinkPHP [ WE CAN DO IT JUST THINK IT ]
// +----------------------------------------------------------------------
// | Copyright (c) 2006-2014 http://thinkphp.cn All rights reserved.
// +----------------------------------------------------------------------
// | Licensed ( http://www.apache.org/licenses/LICENSE-2.0 )
// +----------------------------------------------------------------------
// | Author: liu21st <liu21st@gmail.com>
// +----------------------------------------------------------------------
namespace Think\Cache\Driver;

use Think\Cache;

defined ( 'THINK_PATH' ) or exit ();
/**
 * Memcache缓存驱动
 */
class Memcache extends Cache {
	
	/**
	 * 架构函数
	 * 
	 * @param array $options
	 *        	缓存参数
	 * @access public
	 */
	function __construct($options = array()) {
		if (! extension_loaded ( 'memcache' )) {
			E ( L ( '_NOT_SUPPORT_' ) . ':memcache' );
		}
		
		$options = array_merge ( array (
				'host' => C ( 'MEMCACHE_HOST' ) ? C ( 'MEMCACHE_HOST' ) : '127.0.0.1',
				'port' => C ( 'MEMCACHE_PORT' ) ? C ( 'MEMCACHE_PORT' ) : 11211,
				'timeout' => C ( 'DATA_CACHE_TIMEOUT' ) ? C ( 'DATA_CACHE_TIMEOUT' ) : false,
				'persistent' => false 
		), $options );
		
		$this->options = $options;
		$this->options ['expire'] = isset ( $options ['expire'] ) ? $options ['expire'] : C ( 'DATA_CACHE_TIME' );
		$this->options ['prefix'] = isset ( $options ['prefix'] ) ? $options ['prefix'] : C ( 'DATA_CACHE_PREFIX' );
		$this->options ['length'] = isset ( $options ['length'] ) ? $options ['length'] : 0;
		$func = $options ['persistent'] ? 'pconnect' : 'connect';
		$this->handler = new \Memcache ();
		$options ['timeout'] === false ? $this->handler->$func ( $options ['host'], $options ['port'] ) : $this->handler->$func ( $options ['host'], $options ['port'], $options ['timeout'] );
	}
	
	/**
	 * 读取缓存
	 * 
	 * @access public
	 * @param string $name
	 *        	缓存变量名
	 * @return mixed
	 */
	public function get($name) {
		N ( 'cache_read', 1 );
		return $this->handler->get ( $this->options ['prefix'] . $name );
	}
	
	/**
	 * 写入缓存
	 * 
	 * @access public
	 * @param string $name
	 *        	缓存变量名
	 * @param mixed $value
	 *        	存储数据
	 * @param integer $expire
	 *        	有效时间（秒）
	 * @return boolean
	 */
	public function set($name, $value, $expire = null) {
		N ( 'cache_write', 1 );
		if (is_null ( $expire )) {
			$expire = $this->options ['expire'];
		}
		$name = $this->options ['prefix'] . $name;
		if ($this->handler->set ( $name, $value, 0, $expire )) {
			if ($this->options ['length'] > 0) {
				// 记录缓存队列
				$this->queue ( $name );
			}
			return true;
		}
		return false;
	}
	
	/**
	 * 删除缓存
	 * 
	 * @access public
	 * @param string $name
	 *        	缓存变量名
	 * @return boolean
	 */
	public function rm($name, $ttl = false) {
		$name = $this->options ['prefix'] . $name;
		return $ttl === false ? $this->handler->delete ( $name ) : $this->handler->delete ( $name, $ttl );
	}
	
	/**
	 * 清除缓存
	 * 
	 * @access public
	 * @return boolean
	 */
	public function clear() {
		return $this->handler->flush ();
	}
}
